To evaluate the therapeutic effectiveness and toxicity of BCNU and CCNU administered topically to the skin surface of the above patients. A total of 12 patients were included in this study. None received only BCNU ointment. One received only BCNU ointment. One received only CCNU ointment; the remaining two received CCNU ointment initially and were given BCNU later as a second course of therapy. Five of the 12 patients were treatment failures by other modalities, including surgery and topical 5-FU in propylene glycol. Four of the patients had had X-ray therapy of their acne earlier in life. Four other patients had moderate to severe actinic skin. Two patients had the basal cell nevus syndrome; one had xeroderma pigmentosum. Most patients had lesions of the exposed areas of face and neck. Many patients also had lesions on the trunk and extremities. None of the 12 had the standard variety of BCE histologically; the remaining three were superficial BCE, morphea type of BCE, and the fibroepithelioma type of BCE (Pinkus). There were nine males, three females, varying in age from 23-65.